How is a prime minister chosen

People vote in elections for who they want as the prime minister, although they have to be over the age of 18 to vote in elections.

They are the leader of the party which wins a plurality of the seats in the House of Commons during an election.

The priminister is chosen by a public vote once the contestence have said a speech

Hope that has ansewed your question if it hasn't im sorry

They are chosen by elections. They usually have political backgrounds or experiences. The voters (over the age limit, usually 18, and citizens of the country) will decide on the canadiates. It is very similar to electing a president, but in the United Kingdom, there are also royalties. The royalties have little to none power in the government today, just pretty figureheads.